Gripping device



1965 N. E. ELSAS 3,203,535

GRIPPING DEVICE Filed April 19, 1963 INVENTOR.

B /Vorman /sa$ United States Patent 3,203,535 'GRFPPENG DEVICE Norman E.Elsas, 31181 Maple Drive NE, Atlanta, Ga. Filed Apr. 19, 1963, set. No.274,098 1 Claim. (Cl. '198'180) This invention relates to grippingdevices and more particularly to a gripping device for convenientlygripping fabric, cardboard and other materials so that they can betransported or otherwise processed without dam age.

The processing of fabrics and other materials into garments and variousother articles and items of manufacture frequently requires a grippingdevice for gripping and holding the material so that it may beautomatically transported from one work location to another or so thatwork operations may be conveniently performed upon it at a worklocation. Many of these materials have irregularly textured surfaceswhich make them difficult to grip and hold firmly with previous grippingdevices. This is because a rough or irregular surface provides so littleeffective surface for gripping that considerable mechanical pressuremust be applied. The need for such pressure causes these previousgripping devices to be somewhat complicated and expensive and themechanical pressure exerted by these previous gripping devices oftendamages the material.

The invention disclosed herein provides a convenient and effectivedevice for gripping a variety of light weight materials so that they maybe transported from one work location to another, so that processingoperations may be performed upon them, or so that they may be stored orshipped. The invention is a gripping device comprising a bristle supporthaving a plurality of bristles extending from it and a plate positionedparallel to the bristle support and engaged at an angle by the pluralityof bristles. The bristles are reasonably flexible so as not to be easilybroken. The material to be gripped by the gripping device is insertedbetween the bristles and the plate by a tucking blade, by hand or by anyother suitable means. The plate holds the material against the tips ofthe bristles and the bristles grip the material so that it will not fallfrom the gripping means. Materials being held in the gripping device canbe released from the gripping device by separating the bristles from theplate.

These and other features and advantages of the invention will be moreclearly understood from the following detailed description and theaccompanying drawings in which like characters of reference designatecorresponding parts in all figures and in which:

FIG. 1 is a front elevational view of the gripping device used incombination with an overhead conveyor and shows the gripping devicegripping a panel of fabric, cardboard or similar material fortransporting along the conveyor.

FIG. 2 is a side elevational view of the gripping device as employed inthe conveyor belt embodiment shown in FIG. 1 and as viewed in line 22 inFIG. 1.

FIG. 3 is a side elevational view of the gripping device used incombination with a continuous conveyor belt and a tucking blade.

FIG. 4 is a side elevational view of the gripping device used incombination with a reciprocating rod.

FIG. 5 is an enlarged sectional view of the gripping device.

These figures and the following detailed description disclose apreferred specific embodiment of the invention, but the invention is notlimited to the details disclosed since it may be embodied in otherequivalent forms.

This invention is most easily understood as a gripping device comprisinga plate having a substantially flat material support surface 11 and aplurality of bristles 12 engaging the material support surface of theplate at an angle or. The plurality of bristles 12 extend from thebristle surface 14 of a bristle support 15, and each of the plurality ofbristles 12 has its root 16 embedded in the bristle support 15 in knownmanner. The plurality of bristles 12 may be distributed individuallyover the bristle surface 14 or may be arranged in a plurality of tufts.

The bristle surface 14 of the bristle support 15 is substantiallyparallel to the material support surface 11 of the plate 10 and theplurality of bristles 12 extend parallel to one another between thesetwo surfaces with the tip of each bristle lightly but firmly engagingthe material support surface 11. The bristles 12 all extend at an angle,or, from the bristle support and form the same angle with the materialsupport surface 11. The angle which each of the bristles 12 forms withthe material support surface 11 results in the tip 18 of each bristlebeing displaced a fixed distance along the material support surface 11from that point which each bristle 12 would engage if it wereperpendicular to the material support surface. Since the bristlessubstantially are parallel to one another, the tips 18 of all thebristles 12 are displaced in the same manner, to the same degree, and inthe same direction.

The direction in which the tips of all of the bristles 12 are displacedis the feed direction of the gripping device. This is because materialinserted between the bristle support 15 and the plate 10 in the feeddirection will simply bend the relatively flexible bristles 12 away fromthe plate 10. As a result, semi-rigid or rigid material such ascardboard can be readily inserted into the gripping device by simplyinserting it between the bristle support 15 and plate 10 in the feeddirection.

The direction opposite to the feed direction is the holding direction ofthe gripping device. This is because motion of material between theplate 10 and the tips 18 of the plurality of bristles 12 in thisdirection will cause the bristles 12 to bend toward the plate 10 so asto squeeze the material between the plate 10 and the tips 18 of thebristles 12. The squeezing action of the plurality of bristles 12 holdsfabric, cardboard or any similar material between the plate 10 and thebristle support 15.

If the material being held is a fabric or other porous or irregularlytextured material, the material is held because the tips 18 of thebristles 12 extend into the pores and irregularities of the material andmove with the material as it tends to move in the holding direction.This motion of the tips 18 forces them more deeply into the material andcauses the material to be tightly gripped both by a squeezing action andthe combined rigidity of all bristles 12.

If the material being held is cardboard or some other relatively hardand non-porous material, the material is held because the frictionbetween the tips 18 of the bristles and the material tends to move thetips 18 so as to force the tips 18 more firmly against the material.Whether the material is held by friction or actual insertion of the tips18 of the bristles 12 into irregularities, the more the material tendsto move in the holding direction, the more firmly the material is held.Material inserted in the gripping device can be removed from thegripping device without separating the bristles 12 from the plate 10only by exerting sufiicient force to cause the tips 18 of the bristles12 to come out of the irregularities of a textured surface, to overcomethe friction between the tips 18 and the material, or to cause thebristles 12 to buckle and be displaced in the holding direction.

Whether the bristles 12 will buckle or permit a porous or non-porousmaterial to slide between them and the plate is dependent upon the anglea at which the bristles 12 engage the plate 10 and the rigidity of thebristles 12. The angle or at which the bristles 12 engage the plate 10and the rigidity of the bristles 12 are selected so that buckling of thebristles 12 will not readily occur and so that even though the materialwill slide from between the bristles 12 and the plate 10 before bucklingoccurs, considerable force must be applied by the weight of the materialor other means to cause the material to slide from the holding device.

It has been found that nylon bristles between .075 inch and .2 inch indiameter, extending between /2 inch and 1% inches from the bristlesupport and forming an angle cc of approximately thirty degrees with theplate 10 are adequate for gripping and holding most relatively lightmaterials such as fabrics or cardboard. The quantity of such materialswhich must be gripped by the gripping device varies from one applicationof the gripping device to another. However, the gripping device is bestadapted to material in sheet form and as the size of each unit ofmaterial to be gripped increases, it is simply necessary to increase thenumber of bristles 12 and the area of the material support surface 11engaged by the bristles 12. Thus, by selecting bristles 12 with theproper rigidity, selecting the proper angle or. at which the bristles 12engage the plate 10, and the proper number of bristles 12 and area ofthe material support surface 11 engaged by the bristles 12, theinvention may be embodied in a form suitable for gripping and holdingmost materials in sheet form and many materials with localizedconcentrations of weight.

Moreover, the gripping device can be used in a variety of embodiments.It can be used in embodiments where it is desired to insert materialsuch as sheets of cardboard by hand into the gripping device fortransporting to other locations. Once inserted, the cardboard will beheld firmly enough to prevent its weight from causing it to pull fromthe gripping device.

The combination of the gripping device with an overhead conveyor asshown in FIG. 1 is suitable for such an application.

In such an embodiment, it is simply necessary to force a piece ofcardboard 20 upward between the plate 10 and the bristle support 15 aseach of a plurality of gripping devices moves in known manner along anoverhead conveyor belt 21. The plurality of gripping devices areoriented so that the cardboard is inserted from below the conveyor belt21 in the feed direction and so that gravity will tend to pull thecardboard 20 in the holding direction. When it is desired to remove thecardboard 20 from the gripping device, it is simply necessary toseparate the tips 18 of the bristles 12 from the material supportsurface 11 by any known means. The bristles 12 and the efiective area ofthe gripping device between the tips 18 of the bristles 12 and thematerial support surface 11 are empirically selected so that in theabsence of such separation, the resistance of the gripping device to theremoval of the material will be sufiicient to prevent the material frombeing removed from the gripping device by any degree of force whichwould be reasonably encountered.

As shown in FIG. 3, the gripping device may also be used in a similarembodiment in combination with a tucking blade 22. The tucking blade 22may be the edge of a tucking plate arranged to move in a reciprocatingmanner into and out of the space between the plate 10 and the bristlesupport 15 or it may be the side of a strip or roll to which reciprocalmotion is imparted by a lever 24 pivotally mounted at a point 25. Thegripping device may be one of a plurality of gripping devices carried inknown manner by a conveyor belt 21 driven by a wheel and any known meansmay be used to impart pivotal or slidable motion to the tucking blade22. The material 26 to be gripped by the gripping device is placedbetween the gripping device, oriented with its feed direction away fromthe material 26, and the tucking blade 22 in its withdrawn position.When the tucking blade 22 is moved toward the material 26 in a directioncoinciding with the feed direction of the gripping device, the tuckingblade 22 will carry the material 26 between the plate 10 and the tips 18of the bristles 12. The bristles 12 engage the material 26 and not thetucking blade 22. Thus, when the tucking blade 22 is subsequentlyremoved from between the bristle support 15 and plate 10, the material26 remains in the gripping device where it is firmly gripped. Thetucking blade 22 has a slick surface which causes it to slip easily fromthe material 26 as it withdraws from the gripping device.

In some embodiments of the gripping device it has been found convenientto mount the plate 10 and the bristle support 15 in pivotal relation toeach other. In the embodiment shown in FIG. 3, the plate 10 ispositioned at the end of an arm 28 having a vertical member 29 and thebristle support 15 is positioned at the end of an arm 30 pivotallymounted at the end of the vertical member 2?. The arm 30 is extendedinto a handle 31 which can be grasped to pivot the second arm 30 andmove the bristle support 15 away from the plate 10. The plate 10 andbristle support 15 are urged toward each other by a spring 32 extendingbetween the arm 28 and the arm 30.

In such an embodiment of the gripping device, the material 26 to begripped is inserted into or removed from the gripping device when thebristle support 15 and plate 10 have been separated by using the handle31. This is particularly necessary when the material 26 being gripped isa material such as a delicate fabric. Such a material does not have therigidity to be forced between the bristles 12 and the plate 10 and willbe torn or otherwise damaged if simply pulled from between the bristles12 and the plate 10. The embodiment is also used where it is desired togrip only one of a plurality of layers of material 26. When the grippingdevice is embodied in such an arrangement it is moved in a reciprocatingman ner toward and away from the edge of a pile of material 32comprising a plurality of layers.

With each cycle of operation, the plate passes under the pile ofmaterial 32 and the bristle support 15 is raised by a cam bar 34 andpasses above the pile of material 32. The cam bar 34 raises before thegripping device starts its motion away from the pile of material 32 andthe bristles 12 drop under spring tension to engage the top layer of thepile of material 32. As the gripping device moves away from the pile ofmaterial 32, the tips 18 of the bristles 12 will engage the top layer ofthe pile of material 32 and draw it with the gripping device. Thematerial support surface 11 of the plate 10 is relatively smooth andwill not tend to draw with it the layer of material resting upon it. Asa result, this embodiment of the gripping device will grip only the toplayer of a pile of material and will draw this layer only from the pileof material.

Regardless of the specific arrangement of apparatus in which thegripping device is embodied, the gripping device provides a convenientand effective means for gripping materials without crushing or in anymanner damaging the materials. The gripping device can be used inembodiments where the material has sufiicient rigidity to force itselfinto the gripping device; where the material is forced into the grippingdevice by a tucking blade, roller or hand; or where the device opens andcloses on the material. However, in every embodiment of the grippingdevice, the gripping device will be completely safe to use since thebristles 12 will not injure the hand of an operator which may becomecaught between the plate 10 and the bristle support 14.

It will be obvious to those skilled in the art that many variations maybe made in the embodiments here chosen for-the purpose of illustratingthe present invention without departing from the scope therof as definedby the appended claim.

What is claimed as invention is:

A device for gripping a sheet of material, said device comprising, incombination, a plate having a substantially flat material supportsurface, said plate being positioned on one side of the sheet ofmaterial; a bristle support having a bristle surface substantiallyparallel to the material support surface of the plate, said bristlesupport being on the same side of the sheet of material as the plate; aplurality of parallel bristles, each bristle extending from the bristlesurface and having its tip adjacent to a point on the material supportsurface and each bristle being the hypotenuse of a right triangle havingas a first leg a line of reference perpendicular to the material supportsurface and as a second leg at line of reference parallel to thematerial support surface and extending between the first leg and thebristle; a tucking blade positioned on the opposite side of the sheet ofmaterial from the plate and having a plane of motion substantiallyparallel to the material support surface and which passes through thesheet of material and between the plate and the bristle support; andmeans for reciprocally moving the tucking blade in its plane of motionbetween a position more remote from the plate than the sheet of materialand a position between the plate and the bristle support.

References Cited by the Examiner UNITED STATES PATENTS SAMUEL F.COLEMAN, Primary Examiner.

WILLIAM B. LABORDE, Examiner.

